GB1351546A - Safety devices for centrifugal clutch mechanisms - Google Patents
Safety devices for centrifugal clutch mechanismsInfo
- Publication number
- GB1351546A GB1351546A GB791572A GB791572A GB1351546A GB 1351546 A GB1351546 A GB 1351546A GB 791572 A GB791572 A GB 791572A GB 791572 A GB791572 A GB 791572A GB 1351546 A GB1351546 A GB 1351546A
- Authority
- GB
- United Kingdom
- Prior art keywords
- saw
- clutch
- safety
- chain
- release
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
- B27B17/00—Chain saws; Equipment therefor
- B27B17/08—Drives or gearings; Devices for swivelling or tilting the chain saw
- B27B17/10—Transmission clutches specially designed for chain saws
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
- B27B17/00—Chain saws; Equipment therefor
- B27B17/08—Drives or gearings; Devices for swivelling or tilting the chain saw
- B27B17/083—Devices for arresting movement of the saw chain
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D47/00—Systems of clutches, or clutches and couplings, comprising devices of types grouped under at least two of the preceding guide headings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
Abstract
1351546 Machinery safety devices; friction and positive clutches; clutch-brake combinations R A G JOHANSSON 21 Feb 1972 [24 Feb 1971] 7915/72 Headings F2J F2C F2L and F2U In an injury preventing safety device in a chain saw in which the saw cutting chain 7 is driven from a motor (not shown) via a chain driving sprocket 9 of a centrifugally engaged segmented shoe type friction clutch 59, 61 freely mounted on the motor shaft 49 and connectible thereto by a centrifugally disengagable pivotally mounted (or radially slidable, not shown), positive clutch pawl 77 which is carried by a disc 69 fast on the motor shaft 49 and inwardly sprung biased at 85 into driving engagement at 79, 81 with an extension 83 of the friction clutch hub 59 and normally locked in this position against centrifugal disengagment by a radially projecting lock pin 89 pivotally mounted on the disc 69, a safety device is effective in the event of an operator's hand slipping off the handles or by sudden kick-back of the saw in use to electrically, mechanically, hydraulically or pneumatically downwardly move a release arm 11 to engage and unlock the pin 89 to release the pawl 77 and disengage the friction clutch 59, 61 and additionally engage shoulders 111 or 113 of a ring 101 to apply a brake 107, 109 to rapidly stop the friction clutch 59, 61 and hence the saw cutting chain 7 to prevent injury to the operator. The pawl 77 is re-engagable with the clutch hub 59 via spring 85 and relocked in this engaged position by the centrifugally operated, i.e. engaged pin 89 when the motor shaft speed falls below the engaging speed of the centrifugal friction clutch. As shown, an armature 19 of the safety device is energized via a circuit 21-29 to release the pawl 77 by releasing safety levers 31, &c. in the handles (i.e. dead-man's type handles) of the saw to disengage the friction clutch from the motor shaft for starting purposes, &c., and by a pivotally mounted safety bar 35 arranged in front of the front handle 5 whereby if the operator's hand slips off this front handle, i.e. in the proximity of the saw cutting chain 7, it strikes and rocks the bar and energizes the armature 19 through contacts 39 and circuit 41 to operate the safety release to disengage the motor drive to the saw chain which is rapidly stopped by the brake 101, 109. A saw kick-back sensitive transmitter 43 is additionally incorporated on the chain saw guide bar 7 and responds to sudden kick-back action of the saw to operate, via a circuit 45, the clutch release safety device to stop the saw chain as before. To reduce shock loads in the clutch mechanisms during rapid safety stops of the saw chain, and reconnecting the motor drive thereto, the release arm 11 is resiliently mounted at 117 on its pivot 13 and, additionally, a spring ring friction slip coupling 121 (Fig. 5) is arranged between the driving disc 69 and the clutch hub 59 to maintain a slipping drive to the clutch hub 59 during disengagment of the positive clutch pawl 77. In Fig. 10 (not shown) the armature is replaced by a push rod (143) linked to the safety handles, &c. and operating a band brake (135) having a projecting strip (145) serving in the manner of the release arm 11 (Fig. 1) during a safety stop &c. to initially unlock the pin 89 prior to engagement of the band brake.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE233871A SE354799C (en) | 1971-02-24 | 1971-02-24 | SAFETY DEVICE FOR A CENTRIFUCAL COUPLING WITH A MOTOR SAW |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1351546A true GB1351546A (en) | 1974-05-01 |
Family
ID=20259784
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB791572A Expired GB1351546A (en) | 1971-02-24 | 1972-02-21 | Safety devices for centrifugal clutch mechanisms |
Country Status (13)
Country | Link |
---|---|
JP (1) | JPS597851B1 (en) |
AT (1) | AT332105B (en) |
AU (1) | AU472932B2 (en) |
CA (1) | CA959438A (en) |
DD (1) | DD97928A5 (en) |
FI (1) | FI55459C (en) |
FR (1) | FR2127754A5 (en) |
GB (1) | GB1351546A (en) |
IT (1) | IT947855B (en) |
NO (1) | NO134827C (en) |
PL (1) | PL86045B1 (en) |
SE (1) | SE354799C (en) |
SU (1) | SU511875A3 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0743147B1 (en) * | 1995-05-16 | 1999-08-04 | Makita Corporation | A chain stop device for an electromotive chain saw |
USRE37832E1 (en) | 1995-09-04 | 2002-09-10 | Makita Corporation | Electromotive chain saw |
EP2292376A1 (en) * | 2009-09-02 | 2011-03-09 | Robert Bosch GmbH | Emergency brake system for machine tools |
CN109629501A (en) * | 2019-01-11 | 2019-04-16 | 福建群峰机械有限公司 | A kind of airport sweeper |
CN113483036A (en) * | 2021-07-26 | 2021-10-08 | 刘艳祖 | Constant-speed stable driving control mechanism |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102012211102A1 (en) * | 2012-06-28 | 2014-01-02 | Robert Bosch Gmbh | Tool coupling device |
-
1971
- 1971-02-24 SE SE233871A patent/SE354799C/en unknown
-
1972
- 1972-02-18 AT AT132172A patent/AT332105B/en not_active IP Right Cessation
- 1972-02-21 PL PL15360372A patent/PL86045B1/pl unknown
- 1972-02-21 GB GB791572A patent/GB1351546A/en not_active Expired
- 1972-02-21 DD DD16101272A patent/DD97928A5/xx unknown
- 1972-02-23 FI FI48172A patent/FI55459C/en active
- 1972-02-23 SU SU1751070A patent/SU511875A3/en active
- 1972-02-23 CA CA135,357A patent/CA959438A/en not_active Expired
- 1972-02-23 AU AU39275/72A patent/AU472932B2/en not_active Expired
- 1972-02-23 NO NO55972A patent/NO134827C/no unknown
- 1972-02-24 IT IT2097472A patent/IT947855B/en active
- 1972-02-24 JP JP1933372A patent/JPS597851B1/ja active Pending
- 1972-02-24 FR FR7206217A patent/FR2127754A5/fr not_active Expired
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0743147B1 (en) * | 1995-05-16 | 1999-08-04 | Makita Corporation | A chain stop device for an electromotive chain saw |
USRE37832E1 (en) | 1995-09-04 | 2002-09-10 | Makita Corporation | Electromotive chain saw |
EP2292376A1 (en) * | 2009-09-02 | 2011-03-09 | Robert Bosch GmbH | Emergency brake system for machine tools |
CN102000985A (en) * | 2009-09-02 | 2011-04-06 | 罗伯特.博世有限公司 | Emergency brake system for machine tools |
CN102000985B (en) * | 2009-09-02 | 2015-11-25 | 罗伯特.博世有限公司 | For the emergency braking system of toolroom machine |
CN109629501A (en) * | 2019-01-11 | 2019-04-16 | 福建群峰机械有限公司 | A kind of airport sweeper |
CN109629501B (en) * | 2019-01-11 | 2024-02-20 | 福建群峰机械有限公司 | Airport sweeper |
CN113483036A (en) * | 2021-07-26 | 2021-10-08 | 刘艳祖 | Constant-speed stable driving control mechanism |
Also Published As
Publication number | Publication date |
---|---|
AU3927572A (en) | 1973-08-30 |
SE354799C (en) | 1977-07-28 |
FR2127754A5 (en) | 1972-10-13 |
DD97928A5 (en) | 1973-05-20 |
PL86045B1 (en) | 1976-05-31 |
FI55459C (en) | 1979-08-10 |
DE2207244A1 (en) | 1972-08-31 |
AU472932B2 (en) | 1973-08-30 |
CA959438A (en) | 1974-12-17 |
DE2207244B2 (en) | 1975-09-04 |
AT332105B (en) | 1976-09-10 |
NO134827C (en) | 1976-12-21 |
FI55459B (en) | 1979-04-30 |
SE354799B (en) | 1973-03-26 |
JPS597851B1 (en) | 1984-02-21 |
IT947855B (en) | 1973-05-30 |
NO134827B (en) | 1976-09-13 |
SU511875A3 (en) | 1976-04-25 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |